The present invention relates to crowd control products. More specifically, the invention relates to a pyrotechnic material that carries an irritant, as is commonly used in less-lethal applications; and to a munition that carries such a pyrotechnic material. Such a munition can be propelled by hand, such as a hand grenade. Alternatively, such a munition can be ejected from a launching device such as a firearm; one well known form of such a munition is the 40 mm projectile, which is a relatively large, slow speed, and short distance projectile.
Such a munition typically includes as its active ingredient an irritant. The irritant is dispersed by products of a pyrotechnic reaction, including smoke. The smoke is generated by burning a mixture of fuel and oxidizer. This mixture may be ignited upon launching of the product, or it may be ignited during flight after a predetermined delay period, or upon impact. After the mixture is ignited, the smoke that is produced disperses, and carries with it the irritant.
Historically, CN and CS “tear gas” have been used as the irritant in such munitions. Tear gas is a lachrymatory agent (a chemical compound that irritates eyes to cause tears, pain, and, in some cases, temporary blindness). Pyrotechnics containing tear gas have been effectively manufactured as dry, pelletized material and assembled in munitions.
Another known lachrymatory agent is pepper spray, or Oleoresin Capsicum (“OC”). Aerosols of pepper spray were developed and gained popularity as a more friendly, both physiologically and environmentally, alternative to “tear gas”. While predominantly used in aerosol form, OC has also been manufactured as a blast powder agent.
Characteristics common to all such irritants include a rapid onset (measured in seconds as opposed to minutes); a brief duration of acute effects (10-30 minutes); a relatively low dose required to cause tissue irritation or pain; and a significantly larger dose required to (undesirably) cause death.
One concern with munitions containing an irritant is the tear-producing effect. Specifically, too much tearing can lead to unclear vision, and a lack of clear vision prevents subjects from safely exiting an affected area (crowd dispersion).
Raw OC is classified as an inflammatory, causing acute burning and closing of the eyes, along with severe inflammation of the mucous membranes and upper respiratory system. However, in some formulations it shows a reduced tearing effect and is thus more desirable than “tear gas” chemicals; it affects only the respiratory systems of targeted subjects, leaving their eyes largely undisturbed. This could help exposed subjects to retain sufficient optical clarity for safe egress.
In the past OC has not been successfully used in a product of this type, for several reasons. First, OC is a plant-based extract in liquid phase, and thus is difficult to include as part of a dry fuel and oxidizer mixture amenable to consolidation and ignition (the needed configuration for such a munition). Second, the component of the OC that is responsible for its irritant properties can degrade when exposed to the high temperatures that occur with some pyrotechnic reactions; in contrast, slowing down the reaction by lowering the temperature of combustion can undesirably decrease reaction time and/or result in incomplete burning.